ADU permit cost and fee breakdown in Los Altos, California
GetYourPermit’s researched permit-fee range for a detached accessory dwelling unit in Los Altos, with category estimates and direct reference links used in our investigation.
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ADU size
California prohibits development impact fees for ADUs of 750 sq ft or less, so the 749 / 750 / 751 steps are worth comparing.
Estimated total
GetYourPermit researched range at 750 sq ft
$3,700 – $8,400
This estimate combines our fee-schedule research and project-planning experience. Actual charges vary by parcel, plans, valuation, utilities, and outside agencies.
Typical planning amount
$5,600
Modeled at the 600 sq ft reference.
Where the money goes
These are fee components within the permit process, not separate approvals.
- Separate planning / zoning fee$200 – $650
Shown only where the City bills Planning or zoning review as a separate fee.
- Building plan check$0 – $450
The Building Division’s review of the drawings; part of the Building Permit process.
- Building permit issuance$0 – $250
The permit issuance charge; where plan check is bundled, the combined amount is carried here.
- Separate trade permits$0 – $200
Shown separately only where electrical, plumbing, or mechanical permits are billed outside a combination permit.
- School district fees$2,650 – $3,550
Possible school-district developer fees based on current thresholds and scope.
- Utility fees$600 – $2,300
Possible water, sewer, electrical, meter, or capacity-related charges.
- Processing, inspection & records$150 – $600
Fixed processing, inspection, records, and administrative charges.
- Surcharges, taxes & state fees$100 – $400
Percentage surcharges, construction taxes, and State-mandated charges.
The darker segment is the low end of the range; the full bar is the high end.
Published fee references
Building permit issuance
The permit issuance charge; where plan check is bundled, the combined amount is carried here.
| Fee | Amount | Basis | Source |
|---|---|---|---|
| ADU building permit | $0 | Flat fee | Fee Schedule FY2026-27 — Development Services Building DivisionLocation: FY2026-27 Fee Schedule, Building Permit section, ADU Building Permit rowConfirms: The current City schedule lists ADU Building Permit as $0.00. |
| ADU electrical, mechanical, or plumbing permit | $0 | Flat fee | Fee Schedule FY2026-27 — Development Services Building DivisionLocation: FY2026-27 Fee Schedule, Electrical Mechanical Plumbing Permit section, ADU rowConfirms: The current City schedule lists ADU Electrical, Mechanical or Plumbing Permit as $0.00. |
| Residential construction valuation floor | $591 / sq ft | Per square foot | Fee Schedule FY2026-27 — Development Services Building DivisionLocation: FY2026-27 Fee Schedule, Building Permit section, valuation statementConfirms: The City sets a minimum valuation of $591.39 per square foot for residential and commercial construction. |
Plan check
Review of your drawings for code compliance.
| Fee | Amount | Basis | Source |
|---|---|---|---|
| ADU plan check | $0 | Flat fee | Fee Schedule FY2026-27 — Development Services Building DivisionLocation: FY2026-27 Fee Schedule, Plan Check section, ADU Plan Check rowConfirms: The current City schedule lists ADU Plan Check as $0.00. |
| General building plan check | 135% formula | Formula | Fee Schedule FY2026-27 — Development Services Building DivisionLocation: FY2026-27 Fee Schedule, Plan Check section, Building Plan Check rowConfirms: The City schedule lists general Building Plan Check at 135.00%; it is preserved separately from the ADU zero-fee row. |
Technology & surcharges
Records, technology, and general plan surcharges.
| Fee | Amount | Basis | Source |
|---|---|---|---|
| Technology Surcharge Fee | 5% formula | Formula | Fee Schedule FY2026-27 — Development Services Building DivisionLocation: FY2026-27 Fee Schedule, Fees Assessed at Time of Building Permit IssuanceConfirms: The City lists Technology Surcharge Fee at 5.00% charged based on building permit fee. |
Surcharges, taxes & state fees
Percentage surcharges, construction taxes, and State-mandated charges.
| Fee | Amount | Basis | Source |
|---|---|---|---|
| General Plan Maintenance Fee | 7% formula | Formula | Fee Schedule FY2026-27 — Development Services Building DivisionLocation: FY2026-27 Fee Schedule, Fees Assessed at Time of Building Permit IssuanceConfirms: The City lists General Plan Maintenance Fee at 7.00% charged based on building permit fee. |
These are estimates, not official fees
Use these figures for early budgeting only. They are not a quote, not a government fee determination, and not legal advice. Actual fees depend on your parcel, your plans, your construction valuation, your utility provider, and the fee schedule in force on the day your permit is issued. Confirm every number with Los Altos before you commit money.
City reference pages for verification
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